2015-07-03 10:57, Bruce Richardson: > On Thu, Jul 02, 2015 at 09:04:48PM +0000, Sanford, Robert wrote: > > When one adds multiple post-RX-burst callbacks to a queue, their execution > > order is the opposite of the order in which they are added. For example, we > > add callback A( ), and then we add callback B( ). When we call > > rte_eth_rx_burst, after invoking the device's rx_pkt_burst function, it > > will invoke B( ), and then A( ). The same goes for pre-TX-burst callbacks, > > too. > > > > This is counter-intuitive. Shouldn't we either execute the callbacks in the > > same order that we add them (by changing the internals of the add-APIs), or > > change the add-APIs to allow one to specify whether a callback is added to > > the head or tail of the callback list? At the least, we could document the > > expected behavior. > > Any thoughts on this? > > > Makes sense. I would agree that having the callbacks called in order of > addition > makes more sense. > Having the order configurable might be useful, but would require an API > change, > so I'd only look to change that if it really proves necessary. If the callback > order is consistent and behaves logically (i.e. order of call == order of > add), > can the app not ensure the callbacks are added in the correct order?
+1 to improve behaviour without changing the API. If the applications can manage with a simple DPDK API, it's better for everyone.
